Hello,Thanks for your query. After going through your query I came to know that you are probably suffering from acute lumbar disc prolapse as try to lift your legs straight out in front of you really bothers your lower back. It can be confirmed by MRI scan. There are two treatment options. First option is rest in position of relief(generally lateral position with both knee bend),neurotopics such as mecobalamin and analgesics (Diclofenac three times a day after meals is effective). Sometimes strong analgesic(such as tramadol three times a day after meals) is required. Omeperazole before meals prevent acidity caused by analgesics . This method needs patience as it take longer treatment time. Second option is go for surgical operation(Discectomy). You can discuss with your treating Doctor about it.I do hope that you have found something helpful.If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries. Wishing you good health. Take care.